这里是一个使用日期函数的例子。下面的查询选择了所有记录，其date_col的值是在最后30天以内： 

mysql> SELECT something FROM table 
WHERE TO_DAYS(NOW()) - TO_DAYS(date_col) <= 30; 

DAYOFWEEK(date) 
返回日期date的星期索引(1=星期天，2=星期一, ……7=星期六)。这些索引值对应于ODBC标准。 
mysql> select DAYOFWEEK('1998-02-03'); 
-> 3 

WEEKDAY(date) 
返回date的星期索引(0=星期一，1=星期二, ……6= 星期天)。 
mysql> select WEEKDAY('1997-10-04 22:23:00'); 
-> 5 
mysql> select WEEKDAY('1997-11-05'); 
-> 2 

DAYOFMONTH(date) 
返回date的月份中日期，在1到31范围内。 
mysql> select DAYOFMONTH('1998-02-03'); 
-> 3 

DAYOFYEAR(date) 
返回date在一年中的日数, 在1到366范围内。 
mysql> select DAYOFYEAR('1998-02-03'); 
-> 34 

MONTH(date) 
返回date的月份，范围1到12。 
mysql> select MONTH('1998-02-03'); 
-> 2 

DAYNAME(date) 
返回date的星期名字。 
mysql> select DAYNAME("1998-02-05"); 
-> 'Thursday' 

MONTHNAME(date) 
返回date的月份名字。 
mysql> select MONTHNAME("1998-02-05"); 
-> 'February' 

QUARTER(date) 
返回date一年中的季度，范围1到4。 
mysql> select QUARTER('98-04-01'); 
-> 2 

WEEK(date) 
　 
WEEK(date,first) 
对于星期天是一周的第一天的地方，有一个单个参数，返回date的周数，范围在0到52。2个参数形式WEEK()允许
你指定星期是否开始于星期天或星期一。如果第二个参数是0，星期从星期天开始，如果第二个参数是1，
从星期一开始。 
mysql> select WEEK('1998-02-20'); 
-> 7 
mysql> select WEEK('1998-02-20',0); 
-> 7 
mysql> select WEEK('1998-02-20',1); 
-> 8 

YEAR(date) 
返回date的年份，范围在1000到9999。 
mysql> select YEAR('98-02-03'); 
-> 1998 

HOUR(time) 
返回time的小时，范围是0到23。 
mysql> select HOUR('10:05:03'); 
-> 10 

MINUTE(time) 
返回time的分钟，范围是0到59。 
mysql> select MINUTE('98-02-03 10:05:03'); 
-> 5 

SECOND(time) 
回来time的秒数，范围是0到59。 
mysql> select SECOND('10:05:03'); 
-> 3 

PERIOD_ADD(P,N) 
增加N个月到阶段P（以格式YYMM或YYYYMM)。以格式YYYYMM返回值。注意阶段参数P不是日期值。 
mysql> select PERIOD_ADD(9801,2); 
-> 199803 

PERIOD_DIFF(P1,P2) 
返回在时期P1和P2之间月数，P1和P2应该以格式YYMM或YYYYMM。注意，时期参数P1和P2不是日期值。 
mysql> select PERIOD_DIFF(9802,199703); 
-> 11 

DATE_ADD(date,INTERVAL expr type) 
　 
DATE_SUB(date,INTERVAL expr type) 
　 
ADDDATE(date,INTERVAL expr type) 
　 
SUBDATE(date,INTERVAL expr type) 
这些功能执行日期运算。对于MySQL 3.22，他们是新的。ADDDATE()和SUBDATE()是DATE_ADD()和DATE_SUB()的同义词。
在MySQL 3.23中，你可以使用+和-而不是DATE_ADD()和DATE_SUB()。（见例子）date是一个指定开始日期的
DATETIME或DATE值，expr是指定加到开始日期或从开始日期减去的间隔值一个表达式，expr是一个字符串；它可以以
一个“-”开始表示负间隔。type是一个关键词，指明表达式应该如何被解释。EXTRACT(type FROM date)函数从日期
中返回“type”间隔。下表显示了type和expr参数怎样被关联： type值 含义 期望的expr格式 
SECOND 秒 SECONDS 
MINUTE 分钟 MINUTES 
HOUR 时间 HOURS 
DAY 天 DAYS 
MONTH 月 MONTHS 
YEAR 年 YEARS 
MINUTE_SECOND 分钟和秒 "MINUTES:SECONDS" 
HOUR_MINUTE 小时和分钟 "HOURS:MINUTES" 
DAY_HOUR 天和小时 "DAYS HOURS" 
YEAR_MONTH 年和月 "YEARS-MONTHS" 
HOUR_SECOND 小时, 分钟， "HOURS:MINUTES:SECONDS" 
DAY_MINUTE 天, 小时, 分钟 "DAYS HOURS:MINUTES" 
DAY_SECOND 天, 小时, 分钟, 秒 "DAYS HOURS:MINUTES:SECONDS" 

MySQL在expr格式中允许任何标点分隔符。表示显示的是建议的分隔符。如果date参数是一个DATE值并且你的计算仅仅
包含YEAR、MONTH和DAY部分(即，没有时间部分)，结果是一个DATE值。否则结果是一个DATETIME值。 

mysql> SELECT "1997-12-31 23:59:59" + INTERVAL 1 SECOND; 
-> 1998-01-01 00:00:00 
mysql> SELECT INTERVAL 1 DAY + "1997-12-31"; 
-> 1998-01-01 
mysql> SELECT "1998-01-01" - INTERVAL 1 SECOND; 
-> 1997-12-31 23:59:59 
mysql> SELECT DATE_ADD("1997-12-31 23:59:59", 
INTERVAL 1 SECOND); 
-> 1998-01-01 00:00:00 
mysql> SELECT DATE_ADD("1997-12-31 23:59:59", 
INTERVAL 1 DAY); 
-> 1998-01-01 23:59:59 
mysql> SELECT DATE_ADD("1997-12-31 23:59:59", 
INTERVAL "1:1" MINUTE_SECOND); 
-> 1998-01-01 00:01:00 
mysql> SELECT DATE_SUB("1998-01-01 00:00:00", 
INTERVAL "1 1:1:1" DAY_SECOND); 
-> 1997-12-30 22:58:59 
mysql> SELECT DATE_ADD("1998-01-01 00:00:00", 
INTERVAL "-1 10" DAY_HOUR); 
-> 1997-12-30 14:00:00 
mysql> SELECT DATE_SUB("1998-01-02", INTERVAL 31 DAY); 
-> 1997-12-02 
mysql> SELECT EXTRACT(YEAR FROM "1999-07-02"); 
-> 1999 
mysql> SELECT EXTRACT(YEAR_MONTH FROM "1999-07-02 01:02:03"); 
-> 199907 
mysql> SELECT EXTRACT(DAY_MINUTE FROM "1999-07-02 01:02:03"); 
-> 20102 

如果你指定太短的间隔值(不包括type关键词期望的间隔部分)，MySQL假设你省掉了间隔值的最左面部分。例如，
如果你指定一个type是DAY_SECOND，值expr被希望有天、小时、分钟和秒部分。如果你象"1:10"这样指定值，
MySQL假设日子和小时部分是丢失的并且值代表分钟和秒。换句话说，"1:10" DAY_SECOND以它等价于"1:10" MINUTE_SECOND
的方式解释，这对那MySQL解释TIME值表示经过的时间而非作为一天的时间的方式有二义性。如果你使用确实不正确的日期，
结果是NULL。如果你增加MONTH、YEAR_MONTH或YEAR并且结果日期大于新月份的最大值天数，日子在新月用最大的天调整。 

mysql> select DATE_ADD('1998-01-30', Interval 1 month); 
-> 1998-02-28 

注意，从前面的例子中词INTERVAL和type关键词不是区分大小写的。 
TO_DAYS(date) 
给出一个日期date，返回一个天数(从0年的天数)。 
mysql> select TO_DAYS(950501); 
-> 728779 
mysql> select TO_DAYS('1997-10-07'); 
-> 729669 

TO_DAYS()不打算用于使用格列高里历(1582)出现前的值。 

FROM_DAYS(N) 
给出一个天数N，返回一个DATE值。 
mysql> select FROM_DAYS(729669); 
-> '1997-10-07' 

TO_DAYS()不打算用于使用格列高里历(1582)出现前的值。 

DATE_FORMAT(date,format) 
根据format字符串格式化date值。下列修饰符可以被用在format字符串中： %M 月名字(January……December) 
%W 星期名字(Sunday……Saturday) 
%D 有英语前缀的月份的日期(1st, 2nd, 3rd, 等等。） 
%Y 年, 数字, 4 位 
%y 年, 数字, 2 位 
%a 缩写的星期名字(Sun……Sat) 
%d 月份中的天数, 数字(00……31) 
%e 月份中的天数, 数字(0……31) 
%m 月, 数字(01……12) 
%c 月, 数字(1……12) 
%b 缩写的月份名字(Jan……Dec) 
%j 一年中的天数(001……366) 
%H 小时(00……23) 
%k 小时(0……23) 
%h 小时(01……12) 
%I 小时(01……12) 
%l 小时(1……12) 
%i 分钟, 数字(00……59) 
%r 时间,12 小时(hh:mm:ss [AP]M) 
%T 时间,24 小时(hh:mm:ss) 
%S 秒(00……59) 
%s 秒(00……59) 
%p AM或PM 
%w 一个星期中的天数(0=Sunday ……6=Saturday ） 
%U 星期(0……52), 这里星期天是星期的第一天 
%u 星期(0……52), 这里星期一是星期的第一天 
%% 一个文字“%”。 

所有的其他字符不做解释被复制到结果中。 

mysql> select DATE_FORMAT('1997-10-04 22:23:00', '%W %M %Y'); 
-> 'Saturday October 1997' 
mysql> select DATE_FORMAT('1997-10-04 22:23:00', '%H:%i:%s'); 
-> '22:23:00' 
mysql> select DATE_FORMAT('1997-10-04 22:23:00', 
'%D %y %a %d %m %b %j'); 
-> '4th 97 Sat 04 10 Oct 277' 
mysql> select DATE_FORMAT('1997-10-04 22:23:00', 
'%H %k %I %r %T %S %w'); 
-> '22 22 10 10:23:00 PM 22:23:00 00 6' 
MySQL3.23中，在格式修饰符字符前需要%。在MySQL更早的版本中，%是可选的。 

TIME_FORMAT(time,format) 
这象上面的DATE_FORMAT()函数一样使用，但是format字符串只能包含处理小时、分钟和秒的那些格式修饰符。
其他修饰符产生一个NULL值或0。 
CURDATE() 
　 
CURRENT_DATE 
以'YYYY-MM-DD'或YYYYMMDD格式返回今天日期值，取决于函数是在一个字符串还是数字上下文被使用。 
mysql> select CURDATE(); 
-> '1997-12-15' 
mysql> select CURDATE() + 0; 
-> 19971215 

CURTIME() 
　 
CURRENT_TIME 
以'HH:MM:SS'或HHMMSS格式返回当前时间值，取决于函数是在一个字符串还是在数字的上下文被使用。 
mysql> select CURTIME(); 
-> '23:50:26' 
mysql> select CURTIME() + 0; 
-> 235026 

NOW() 
　 
SYSDATE() 
　 
CURRENT_TIMESTAMP 
以'YYYY-MM-DD HH:MM:SS'或YYYYMMDDHHMMSS格式返回当前的日期和时间，取决于函数是在一个字符串还是在数字的
上下文被使用。 
mysql> select NOW(); 
-> '1997-12-15 23:50:26' 
mysql> select NOW() + 0; 
-> 19971215235026 

UNIX_TIMESTAMP() 
　 
UNIX_TIMESTAMP(date) 
如果没有参数调用，返回一个Unix时间戳记(从'1970-01-01 00:00:00'GMT开始的秒数)。如果UNIX_TIMESTAMP()用一
个date参数被调用，它返回从'1970-01-01 00:00:00' GMT开始的秒数值。date可以是一个DATE字符串、一个DATETIME
字符串、一个TIMESTAMP或以YYMMDD或YYYYMMDD格式的本地时间的一个数字。 
mysql> select UNIX_TIMESTAMP(); 
-> 882226357 
mysql> select UNIX_TIMESTAMP('1997-10-04 22:23:00'); 
-> 875996580 

当UNIX_TIMESTAMP被用于一个TIMESTAMP列，函数将直接接受值，没有隐含的“string-to-unix-timestamp”变换。 

FROM_UNIXTIME(unix_timestamp) 
以'YYYY-MM-DD HH:MM:SS'或YYYYMMDDHHMMSS格式返回unix_timestamp参数所表示的值，取决于函数是在一个字符串
还是或数字上下文中被使用。 
mysql> select FROM_UNIXTIME(875996580); 
-> '1997-10-04 22:23:00' 
mysql> select FROM_UNIXTIME(875996580) + 0; 
-> 19971004222300 

FROM_UNIXTIME(unix_timestamp,format) 
返回表示 Unix 时间标记的一个字符串，根据format字符串格式化。format可以包含与DATE_FORMAT()函数列出的条
目同样的修饰符。 
mysql> select FROM_UNIXTIME(UNIX_TIMESTAMP(), 
'%Y %D %M %h:%i:%s %x'); 
-> '1997 23rd December 03:43:30 x' 

SEC_TO_TIME(seconds) 
返回seconds参数，变换成小时、分钟和秒，值以'HH:MM:SS'或HHMMSS格式化，取决于函数是在一个字符串还是在数字
上下文中被使用。 
mysql> select SEC_TO_TIME(2378); 
-> '00:39:38' 
mysql> select SEC_TO_TIME(2378) + 0; 
-> 3938 

TIME_TO_SEC(time) 
返回time参数，转换成秒。 
mysql> select TIME_TO_SEC('22:23:00'); 
-> 80580 
mysql> select TIME_TO_SEC('00:39:38'); 
-> 2378

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Unpacking...
Checksumming...
Extracting...
UnZipSFX 5.50 of 17 February 2002, by Info-ZIP (Zip-Bugs@lists.wku.edu).
  inflating: jdk-6u10-beta-linux-i586.rpm
  inflating: sun-javadb-common-10.4.1-3.1.i386.rpm
  inflating: sun-javadb-core-10.4.1-3.1.i386.rpm
  inflating: sun-javadb-client-10.4.1-3.1.i386.rpm
  inflating: sun-javadb-demo-10.4.1-3.1.i386.rpm
  inflating: sun-javadb-docs-10.4.1-3.1.i386.rpm
  inflating: sun-javadb-javadoc-10.4.1-3.1.i386.rpm
Preparing...                ########################################### [100%]
   1:jdk                    ########################################### [100%]
Unpacking JAR files...
        rt.jar...
        jsse.jar...
        charsets.jar...
        tools.jar...
        localedata.jar...
        plugin.jar...
        javaws.jar...
        deploy.jar...
Installing JavaDB
Preparing...                ########################################### [100%]
   1:sun-javadb-common      ########################################### [ 17%]
   2:sun-javadb-core        ########################################### [ 33%]
   3:sun-javadb-client      ########################################### [ 50%]
   4:sun-javadb-demo        ########################################### [ 67%]
   5:sun-javadb-docs        ########################################### [ 83%]
   6:sun-javadb-javadoc     ########################################### [100%]

Done.
[root@localhost java]# vi /etc/profile
[root@localhost java]# source /etc/profile

[root@localhost java]#
[root@localhost java]# env
KDE_MULTIHEAD=false
SSH_AGENT_PID=5201
HOSTNAME=localhost.localdomain
TERM=xterm
SHELL=/bin/bash
HISTSIZE=1000
GTK2_RC_FILES=/etc/gtk-2.0/gtkrc:/root/.gtkrc-2.0:/root/.kde/share/config/gtkrc-2.0
KDE_NO_IPV6=1
GTK_RC_FILES=/etc/gtk/gtkrc:/root/.gtkrc:/root/.kde/share/config/gtkrc
GS_LIB=/root/.fonts
WINDOWID=37748743
QTDIR=/usr/lib/qt-3.3
QTINC=/usr/lib/qt-3.3/include
KDE_FULL_SESSION=true
USER=root
LS_COLORS=no=00:fi=00:di=00;34:ln=00;36:pi=40;33:so=00;35:bd=40;33;01:cd=40;33;01:or=01;05;37;41:mi=01;05;37;41:ex=00;32:*.cmd=00;32:*.exe=00;32:*.com=00;32:*.btm=00;32:*.bat=00;32:*.sh=00;32:*.csh=00;32:*.tar=00;31:*.tgz=00;31:*.arj=00;31:*.taz=00;31:*.lzh=00;31:*.zip=00;31:*.z=00;31:*.Z=00;31:*.gz=00;31:*.bz2=00;31:*.bz=00;31:*.tz=00;31:*.rpm=00;31:*.cpio=00;31:*.jpg=00;35:*.gif=00;35:*.bmp=00;35:*.xbm=00;35:*.xpm=00;35:*.png=00;35:*.tif=00;35:
SSH_AUTH_SOCK=/tmp/ssh-JCjHpF5168/agent.5168
KDEDIR=/usr
SESSION_MANAGER=local/localhost.localdomain:/tmp/.ICE-unix/5379
XDG_CONFIG_DIRS=/etc/kde/xdg:/etc/xdg
KONSOLE_DCOP=DCOPRef(konsole-5629,konsole)
MAIL=/var/spool/mail/root
PATH=/usr/lib/qt-3.3/bin:/usr/kerberos/sbin:/usr/kerberos/bin:/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/usr/X11R6/bin:/root/bin:/usr/java/jdk1.6.0_10/bin
DESKTOP_SESSION=kde
QT_IM_MODULE=scim
GDM_XSERVER_LOCATION=local
KONSOLE_DCOP_SESSION=DCOPRef(konsole-5629,session-1)
INPUTRC=/etc/inputrc
PWD=/usr/local/java
JAVA_HOME=/usr/java/jdk1.6.0_10
XMODIFIERS=@im=SCIM
KDE_IS_PRELINKED=1
LANG=zh_CN.UTF-8
GDMSESSION=kde
XERCESCROOT=/home/soft/xerces-c-src_2_8_0
SSH_ASKPASS=/usr/libexec/openssh/gnome-ssh-askpass
SHLVL=3
HOME=/root
XCURSOR_THEME=default
LOGNAME=root
QTLIB=/usr/lib/qt-3.3/lib
CVS_RSH=ssh
CLASSPATH=/usr/java/jdk1.6.0_10/lib:.
DBUS_SESSION_BUS_ADDRESS=unix:abstract=/tmp/dbus-FGw3oIRYzq,guid=7c118c48fd191781b3038c562a018700
LESSOPEN=|/usr/bin/lesspipe.sh %s
DISPLAY=:0.0
GTK_IM_MODULE=scim-bridge
G_BROKEN_FILENAMES=1
COLORTERM=
XAUTHORITY=/tmp/.gdmYVAKEU
_=/bin/env
[root@localhost java]# java -version
java version "1.4.2"
gij (GNU libgcj) version 4.1.2 20071124 (Red Hat 4.1.2-42)

Copyright (C) 2006 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
[root@localhost java]#    

　　因为Centos 5.0 的yum 版本已经上升到3,所以yum有个插件名叫

　　yum-fastestmirror

　　这个插件能检查到你机器最快的镜像

　　这个插件安装也很简单

　　yum -y install yum-fastestmirror

　　然后你再使用yum安装其他软件就会发现速度快多了

The latest version of Ubuntu (8.04 a.k.a. Ubuntu Hardy - the world’s most popular Linux distribution) came out yesterday on April 24th. I downloaded it right away to play with on VMware Fusion, my Mac virtualization tool of choice (though I’ve now been told this works in VMware Workstation and VMware Player on the PC too!). It worked pretty well out of the box, with even seamless mouse support working right away, but I needed, of course, to install VMware Tools too, as any good VMware user would do. From there, things turned sour, and I was bombarded with error messages similar to:

In file included from /tmp/vmware-config8/vmblock-only/linux/os.h:35,
from /tmp/vmware-config8/vmblock-only/linux/block.c:26:
/tmp/vmware-config8/vmblock-only/./include/compat_wait.h:78: error: conflicting types for ‘poll_initwait’
include/linux/poll.h:65: error: previous declaration of ‘poll_initwait’ was here
In file included from /tmp/vmware-config8/vmblock-only/linux/vmblockInt.h:40,
from /tmp/vmware-config8/vmblock-only/linux/block.c:29:
/tmp/vmware-config8/vmblock-only/./include/vm_basic_types.h:184: error: conflicting types for ‘uintptr_t’
include/linux/types.h:40: error: previous declaration of ‘uintptr_t’ was here
make[2]: *** [/tmp/vmware-config8/vmblock-only/linux/block.o] Error 1
make[1]: *** [_module_/tmp/vmware-config8/vmblock-only] Error 2
make[1]: Leaving directory `/usr/src/linux-headers-2.6.24-16-generic’
make: *** [vmblock.ko] Error 2
make: Leaving directory `/tmp/vmware-config8/vmblock-only’
Unable to build the vmblock module.

After banging my head against the wall for a while, trying a “vmware-any-any” patch that didn’t quite do the trick, and scouring the VMWare Fusion and Ubuntu Forums, I eventually came across a link to a page that described how to solve the problem. The credit for this solution rests entirely on the guy who wrote that page and a guy called Mufassa who posted a shorter explanation to the VMware Fusion forums.

I wanted to write this up into a proper blog post though for two reasons. Firstly, I wanted to show how to fix the problem in a more, direct line by line way (just in case you’re a novice or would rather follow some command line instructions). Secondly, I know posts on this blog appear in Google very quickly, so I want people Googling for “vmware fusion” and “ubuntu hardy” (like I was earlier) to find this page and have their problem solved! So, credit to those other guys, but..

Steps To Getting VMware Tools installed on Ubuntu Hardy under VMware Fusion:

Use the “Install VMware Tools” option in VMWare Fusion, and drag the .tar file (not the RPM!) to the Ubuntu desktop.

Open a Terminal (Applications menu -> Accessories -> Terminal). We’ll do all the work from the Terminal. First, we need to install some dependencies:

sudo apt-get install build-essential libgtk2.0-dev
sudo apt-get install libproc-dev libdumbnet-dev xorg-dev
cd Desktop/

wget http://mesh.dl.sourceforge.net/sourceforge/open-vm-tools/open-vm-tools-2008.04.14-87182.tar.gz

Next, we need to unpack the tar files we have at hand:

tar xzvf VMware*.gz
tar xzvf open-vm-tools*.gz

Next, we’ll build the open-vm-tools:

cd open-vm-tools-2008.04.14-87182/
./configure && make
cd modules/linux/

In the modules/linux folder we have the vmblock, vmhgfs, vmmemctl, vmsync and vmxnet modules that we need to tar up and place into the official VMware tools tarball:

for i in *; do mv ${i} ${i}-only; tar -cf ${i}.tar ${i}-only; done
cd ../../..

mv -f open-vm-tools-2008.04.14-87182/modules/linux/*.tar vmware-tools-distrib/lib/modules/source/

Now we can run the regular VMware tools installer:

cd vmware-tools-distrib/
sudo ./vmware-install.pl

Once this is done, the best tactic is to restart Ubuntu entirely. Once you boot back up, things should seem a bit smoother. The resolution of the VM will stick to the size of the VM, etc, and you can now drag files directly into Ubuntu Hardy from your Mac desktop!

Note: A few of the lines of code you need to use above are single lines of code but spread over multiple lines on your screen when viewing this blog. Either make your browser wider, or copy and paste them into a text editor before continuing.

sudo gedit /etc/X11/xorg.conf

将"Input Device" 这个section的

Option "Protocol" "ps/2"

替换为

Option "Protocol" "IMPS/2"

我的xorg.conf原来没有这个语句，就添加了。

Ctrl+alt+backspace 重启X，还是没有效果。

网上在查了下，发现我的配置还少了句：

Option "Emulate3Buttons" "yes“

另外，我的驱动是: Driver "vmmouse"

而一般常见的是: Driver "mouse"

完整的配置段落：

Section "InputDevice"

Identifier "Configured Mouse"

Driver "vmmouse"

Option "Protocol" "ImPS/2"

Option "CorePointer"

Option "Device" "/dev/input/mice"

Option "ZAxisMapping" "4 5"

Option "Emulate3Buttons" "yes"

EndSection

这种开发方式生产力并不高，若只是开发学习用的小程序则影响不大，但若要开发大型项目时，程序档案个数众多，需要用project或solution的方式管理；且debug时breakpoint的加入，单步执行，观察变量变化等，都需要更可视化的方式才能够增加生产力；最重要的，由于现在的程序语言皆非常的庞大，又有复杂的函式库，要程序员熟记所有的程序语法和function名称，实在很困难，所以语法提示(Intellisense)的功能就非常重要，这些就必须靠IDE来达成。

在Windows平台上，若要开发C/C++程序，我们有Microsoft Visual Studio、Borland C++ Builder可用，这些都是很好用的IDE，但可惜仅能在Windows下使用，但是在Linux平台呢?基于以下理由，我推荐使用Eclipse开发C/C++程序：


1. Eclipse是一个用Java所撰写IDE，因此可跨平台，所以在Linux和Windows平台下皆可使用Eclipse，可降低程序员熟析IDE的学习曲线。


2. Eclipse虽然主要拿来开发Java程序，但事实上Eclipse为一个『万用语言』的IDE，只要挂上plugin后，就可以在Eclipse开发各种语言程序，所以我们只要挂上CDT(C/C++ Development Toolkit)后，就可以在Eclipse开发C/C++程序，除此之外，目前的主流程序语言，如C/C++、C#、Java、PHP、Perl、Python、Ruby、Rebol、JavaScript、SQL、XML、UML等，皆可在Eclipse上撰写，所以只要熟析Eclipse的IDE环境，将来若开发其它语言程序，就不用再重新学习IDE环境了。


3. 最重要的，Eclipse和CDT是Open Source且完全免费，取得相当容易，事实上Fedora 5已经包含Eclipse和CDT了，虽然预设Fedara 5安装时并没有含Eclipse，只要手动另外加选即可。

B. 如何在Linux下安装Eclipse和CDT? 
i. 由Linux Distribution安装Eclipse，Fedora 5就内含Eclipse和CDT。

ii. 手动安装
  1. 下载档案
    A、 下载JRE(Java Runtime Environment) 。(http://java.sun.com/javase/downloads/index.jsp)

    B、 下载Eclipse SDK。(http://www.eclipse.org/downloads/)

    C、 下载CDT。(http://www.eclipse.org/cdt/downloads.php)

  2. 安装
    A、 安装JRE
      i. [root@localhost ~]#mkdir /usr/local/java

      ii. (将档案jre-1_5_0_09-linux-i586-rpm.bin下载到/usr/local/java目录下)

      iii. (超级用户模式)
      [root@localhost ~]#su            

      iv.  [root@localhost ~]#cd /usr/java

      v. (将您所下载的档的权限更改为可执行)
      [root@localhost java]#chmod a+x jre-1_5_0_09-linux-i586-rpm.bin 

      vi. (启动安装过程)
      [root@localhost java]#./jre-1_5_0_09-linux-i586-rpm.bin
      (此时将显示二进制许可协议，按控格显示下一页，读完许可协议后，输入 『yes』继续安装。此时会将解压缩，产生jre-1_5_0_9-linux-i586.rpm)


      vii. (安装jre-1_5_0_9-linux-i586.rpm)
      [root@localhost java]#rpm –ivh jre-1_5_0_9-linux-i586.rpm

      (此时会将JRE装在/usr/java/jre1.5.0_09目录下)

      viii. (设定环境变量，让Linux能找到JRE)
      [root@localhost java]#vi /etc/profile
      (将以下内容加入在档案后面)

1PATH=$PATH:/usr/java/jre1.5.0_09/bin
2export JAVA_HOME=/usr/java/jre1.5.0_09
3export CLASSPATH=$JAVA_HOME/lib:.

      (存盘后，重新启动Linux)

      ix. (测试Java是否安装成功)
      [root@localhost ~]#java –version


    B、 安装Eclipse SDK
      i. (将档案eclipse-SDK-3.2.1-linux-gtk.tar.gz下载到桌面)

      ii. [root@localhost ~]#cd /usr/local

      iii. [root@localhost local]#cp ~Desktop/eclipse-SDK-3.2.1-linux-gtk.tar.gz .    

      iv. (将eclipse-SDK-3.2.1-linux-gtk.tar.gz解压缩)
      [root@localhost local]#tar –zxvf eclipse-SDK-3.2.1-linux-gtk.tar.gz

      v. [root@localhost local]#cd eclipse

      vi. (执行Eclipse)
      [root@localhost eclipse]#./eclipse

      vii. (Select a workspace)
      (将Use this as the default and do not ask again打勾，以后就不会出现这个窗口)


      (第一次执行Eclipse会出现此error，因为没有任何Eclipse设定档，所以无法读取，第二次执行Eclipse就无此错误讯息，按OK继续。)


      (Eclipse主画面)


    C、 安装CDT
      i. (将档案org.eclipse.cdt-3.1.1-linux.x86.tar.gz下载到桌面)

      ii. [root@localhost ~]#cp ~/Desktop/org.eclipse.cdt-3.1.1-linux.x86.tar.gz .

      iii. (将org.eclipse.cdt-3.1.1-linux.x86.tar.gz解压缩)
      [root@localhost ~]#tar –zxvf org.eclipse.cdt-3.1.1-linux.x86.tar.gz
      (档案将解到~/eclipse目录下)

      iv. (安装CDT plugin)
      [root@localhost ~]cp –r eclipse/plugins/. /usr/local/eclipse/plugins/

      v. (启动Eclipse，多了C和C++ Project支持) 
   

C. 如何在Eclipse上开发C/C++程序?
i. 建立Hello Word project
  1. 建立C/C++ project


  2. 选择Managed Make C++ Project(若选择Managed Make C++ Project，Eclipse会自动为我们建立make file；若选择Standard Make C++ Project，则必须自己写make file。)


  3. 输入Project name


  4. 选择Project类型(如执行档或Library，这里选择执行档即可)


  5. 额外的设定


  6. Open Associated Perspective?(选Yes继续)


  7. 建立C++ Source File


8. 输入C++ Source File檔名


  9. 输入C++程序代码


  10. 执行程序(显示在下方的Console区)


ii. 如何在Eclipse CDT中Debug C/C++程序?
1. 在Eclipse中Debug，就如同在一般IDE中Debug一样，只要在程序代码的左方按两下，就可加入breakpoint。


  2. 启动Debug


  3. Debug设定，按Debug开始Debug


  4. 单步执行，显示变量变化


E. 结论
Eclipse为Linux在C/C++开发提供一个完善的IDE环境，事实上，以我用过众多IDE的经验，除了Visual Studio最方便外，Eclipse的好用也直追Visual Studio，并且超越Borland C++ Builder及Dev C++，虽然安装上比较麻烦，但只要依照本文介绍一步一步的设定，就一定可完成Eclipse设定，若想要在Windows平台使用gcc compiler，也建议使用Eclipse + CDT + MinGW的组合。

See Also
[转载] Eclipse + CDT + MinGW 安装方法

Reference
1. 为Linux手动下载和安装Java Runtime Enrironment(JRE)的说明
(http://www.java.com/zh_CN/download/help/5000010500.xml)
2. Eclipse 3.0 CDT on Linux
(http://www.autexier.de/jmau/dev/CDT/cdt.html)

# service network restart
OR
# /etc/init.d/network restart

To start Linux network service:
# service network start

To stop Linux network service:
# service network stop

Debian Linux command to reload or restart network:
# /etc/init.d/networking restart

To start Linux network service:
# /etc/init.d/networking start

To stop Linux network service:
# /etc/init.d/networking stop

Ubuntu Linux user use sudo command with above Debian Linux command:
# sudo /etc/init.d/networking restart

To start Linux network service:
# sudo /etc/init.d/networking start

To stop Linux network service:
# sudo /etc/init.d/networking stop

Also before you disable your firewall, you must disconnect your computer from all networks, including the Internet to avoid damage

You would like to Halt linux firewall or stop linux firewall (i.e. flush iptables rules). First login as root user.

Option A - If you are redhat Linux user type command:

If you are using Red Hat (RHEL) / CentOS / Fedora Core Linux, use the following command:

/etc/init.d/iptables stop

OR

service iptables stop

Option B - If you are Debian Linux user type following commands one by one

iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT

First login as root user. Now type the following command as per your Linux distro:

A) If you are using mysql on RedHat Linux (Fedora Core/Cent OS) then use following command:

* To start mysql server:
# /etc/init.d/mysqld start

* To stop mysql server:
# /etc/init.d/mysqld stop

* To restart mysql server
# /etc/init.d/mysqld restart

Tip: Redhat Linux also supports service command, which can be use to start, restart, stop any service:
# service mysqld start
# service mysqld stop
# service mysqld restart

(B) If you are using mysql on Debian Linux then use following command:

* To start mysql server:
# /etc/init.d/mysql start

* To stop mysql server:
# /etc/init.d/mysql stop

* To restart mysql server
# /etc/init.d/mysql restart

More MySQL articles are here and here.

以下方法，可使修改直接生效：
修改ip地址
# ifconfig eth0 192.168.0.20 netmask 255.255.255.0

修改default gateway
# route add default gw 192.168.0.254

修改dns
修改/etc/resolv.conf

修改host name
# hostname fc2
启动生效:
修改/etc/sysconfig/network

ifconfig eth0 新ip
然后编辑/etc/sysconfig/network-scripts/ifcfg-eth0，修改ip

[aeolus@db1 network-scripts]$ vi ifcfg-eth0

DEVICE=eth0
ONBOOT=yes
BOOTPROTO=static
IPADDR=219.136.241.211
NETMASK=255.255.255.128
GATEWAY=219.136.241.254

[aeolus@db1 etc]$ vi resolv.conf

nameserver 202.96.128.68
nameserver 219.136.241.206

－－－－－－－－－－－－－－－－－－－－－－－
Linux下修改网卡IP和网关


建议通过终端字符方式下来修改
一修改IP地址
vi /etc/sysconfig/network-scripts/ifcfg-eth0
DEVICE=eth0
BOOTPROTO=none
BROADCAST=192.168.1.255
IPADDR=192.168.1.33
NETMASK=255.255.255.0
NETWORK=192.168.1.0
ONBOOT=yes
USERCTL=no
PEERDNS=no
TYPE=Ethernet
~

vi /etc/sysconfig/network-scripts/ifcfg-eth1

DEVICE=eth1
ONBOOT=yes
BOOTPROTO=none
IPADDR=192.168.2.34
NETMASK=255.255.255.0
USERCTL=no
PEERDNS=no
TYPE=Ethernet
NETWORK=192.168.2.0
BROADCAST=192.168.2.255
二修改网关
vi /etc/sysconfig/network

NETWORKING=yes
HOSTNAME=Aaron
GATEWAY=192.168.1.1

三重新启动网络配置
/etc/init.d/network restart



-----------------------------------------------------------------------------------

修改配置文件

/etc/sysconfig/network-scripts/ 下有配置文件

比如文件：ifcfg-eth0 代表是以太网实际网卡0的配置文件

比如文件：ifcfg-eth0:1 代表是以太网实际网卡0的配置文件

域名服务器配置文件：/etc/ resolv.conf

修改ip地址
即时生效:
# ifconfig eth0 192.168.0.20 netmask 255.255.255.0
启动生效:
修改/etc/sysconfig/network-scripts/ifcfg-eth0

修改default gateway
即时生效:
# route add default gw 192.168.0.254
启动生效:
修改/etc/sysconfig/network-scripts/ifcfg-eth0

修改dns
修改/etc/resolv.conf
修改后可即时生效，启动同样有效

修改host name
即时生效:
# hostname fc2
启动生效:
修改/etc/sysconfig/network